Monocyte activation in persons living with HIV and tuberculosis coinfection

OBJECTIVES To characterize monocyte subsets and activation in persons living with HIV (PLWH) with tuberculosis coinfection. DESIGN Cross-sectional study within a cohort of PLWH and HIV-uninfected participants at the Joint Clinical Research Centre in Kampala, Uganda. METHODS Participants were at least 45 years old with at least one cardiovascular risk factor. PLWH had an HIV viral load 1000 copies/ml or less on stable antiretroviral therapy prior to cohort entry. QuantiFERON-TB testing was performed to define latent tuberculosis infection (LTBI). Prior active TB was defined by self-report and verified by medical records. Blood was stained with monocyte subset markers (CD14+, CD16), CD62p, CD69, CX3CR1, HLA-DR, and tissue factor, and examined with flow cytometry. RESULTS One hundred and twenty-five participants (83 PLWH and 42 without HIV) were included. Median CD4+ count was 582 cells/μl in PLWH. PLWH had a higher frequency of total monocytes (4.3% vs. 3.2%; P